WDM (Wavelength Division Multiplexing)

What is WDM? – Basics of our CWDM & DWDM system
The IT refers to a medium where information is transmitted via a link. If two locations want to communicate with each other, one link is sufficient. To connect more locations more links are required What if only one link e.g. between two cities is available, but more applications shall be connected? Using the WDM technology, fiber optic links can be utilized for data transmission more efficiently.

 

The idea of xWDM technology

Each application is allocated to a dedicated color (wavelength) to communicate with a remote station. The advantage is that different colors can be simultaneously transmitted using one pair of fiber. For this purpose a multiplexer combines all different colors which will then be transmitted to the remote station over one pair of fiber. At the remote site the combined signal is separated again into different colors by a demultiplexer. Generally only one light beam with one wavelength is transferred over a pair of fiber. The wavelength multiplexing technology provides the ability to transmit more light beams, each having different wavelengths, using the same optical link. Due to the fact that wavelengths do not interfere, single light beams can be separated from each other using simple filters. A laser serves as the source of light and light-sensitive diode as receiver unit. Wavelength multiplexing is differentiated in CWDM (Coarse Wavelength Division Multiplexing) and DWDM (Dense Wavelength Division Multiplexing) technology. Advantage: With the use of WDM, it is possible to transfer nearly 1 Tbps (C-band) via one pair of fiber today.

Choosing of the appropriate wavelength
By the use of appropriate transceivers (SFP, XFP etc.) with different power budget ranges from a few 100 m up to 160 km can be achieved. A major factor in the range is – next to the power budget of the transceiver – the used wavelength as a fiber has a specific attenuation behaviour for each wavelength. The higher the attenuation, the lower the overall distance. With a careful selection of the wavelength a higher range and better signal quality can be achieved.

Need more information, Welcome Contact Ivy, sales6@htfuture.com

Physical phenomena of optical transmission media

Physical phenomena of optical transmission media

Intermodal dispersion

With a correspondingly large cross section, a signal is reflected between the core and the cladding of the fiber. The group velocity of light propagating in a multimode fiber depends also on the propagation of different modes (Differential Mode Delay). This leads to a broadening of the signal.

Polarization mode dispersion

Optical fiber shows the effect of birefringent, caused by external influences such as bending, torsion, as well as inhomogeneity of the core. This results in different propagation velocities for the two orthogonal  polarization states (Differential Group Delay) and therefore in a pulse broadening. A reduction of this effect can be achieved, as far as possible, by an exact geometry of the fiber. External influences are minimized by careful handling during installation of the fiber.

Four-wave-mixing
It can occur that three different frequency components propagate together in a an optical fiber, creating a fourth frequency component. Similar to cross-talk - these four different frequency components interact via four-wave mixing with neighboured ones. This effect is reduced in case of non-zero chromatic dispersion of the fiber.  If all four different components A degenerate four-wave mixing occours, where the frequencies coincide.

Chromatic dispersion

The chromatic dispersion describes the phenomenon when the group velocity of light propagating in a fiber depends on the optical frequency. The resulting differential group delay between different frequency components lead to a distortion of the received signal and a limitation of distances in a DWDM network.  This effect is well handled by various methods.

Chromatic dispersion and use of fiber-bragg-gratings for compensation

Chromatic dispersion can be compensated by various techniques, e.g. by the use of an fiber-bragg-grating. In principle a fiber-bragg-grating chance its refractive index with penetration depth of light. An incoming pulse that is broadened, the different spectral components travels on different paths within the grating.
The resulting time delay results in a narrowing of the pulse and thus to a compensation of the chromatic dispersion.

If Need more information about fiber optic products and WDM systematic solution,
Contact Ivy,  sales6@htfuture.com             www.htfuture.com

What is WDM? WDM (Wavelength Division Multiplexing)

WDM (Wavelength Division Multiplexing)
What is WDM? – Basics of our CWDM & DWDM system
The IT refers to a medium where information is transmitted via a link. If two locations want to
communicate with each other, one link is sufficient. To connect more locations more links are required What if only one link e.g. between two cities is available, but more applications shall be connected? Using the WDM technology, fiber optic links can be utilized for data transmission more efficiently.

The idea of xWDM technology
Each application is allocated to a dedicated color (wavelength) to communicate with a remote station. The advantage is that different colors can be simultaneously transmitted using one pair of fiber. For this purpose a multiplexer combines all different colors which will then be transmitted to the remote station over one pair of fiber. At the remote site the combined signal is separated again into different colors by a demultiplexer. Generally only one light beam with one wavelength is transferred over a pair of fiber. The wavelength multiplexing technology provides the ability to transmit more light beams, each having different wavelengths, using the same optical link. Due to the fact that wavelengths do not interfere, single light beams can be separated from each other using simple filters. A laser serves as the source of light and light-sensitive diode as receiver unit. Wavelength multiplexing is differentiated in CWDM (Coarse Wavelength Division Multiplexing) and DWDM (Dense Wavelength Division Multiplexing) technology. Advantage: With the use of WDM, it is possible to transfer nearly 1 Tbps (C-band) via one pair of fiber today.Choosing of the appropriate wavelength
By the use of appropriate transceivers (SFP, XFP etc.) with different power budget ranges from a few 100 m up to 160 km can be achieved. A major factor in the range is – next to the power budget of the transceiver – the used wavelength as a fiber has a specific attenuation behaviour for each wavelength. The higher the attenuation, the lower the overall distance. With a careful selection of the wavelength a higher range and better signal quality can be achieved.

If need DWDM CWDM related products, welcome to contact Ivy. 

Tel: +86 755 23777185 | Email/Skype: sales6@htfuture.com

Shenzhen htfuture Co., Ltd

Shenzhen htfuture Co., Ltd is a professional supplier of fiber optic products and WDM systematic solution. Was built by a team who has more than 10-year experiences in optical communication product R&D, fiber solution, component developing and manufacturing.

HTFuture supplies a broad range of communication solutions products including wavelength division multiplexer(WDM/CWDM/DWDM/OADM), Fiber Optic Transceivers(SFP, SFP+, XFP, 10G QSFP+, 40G QSFP+ and 100G CFP2), OEO Converter Repeater, Ethernet Media Converter, Fiber Optical Patch cord and Fiber Optical assembly. Currently our products are widely used in Telecommunication, CATV, FTTX, WANs, LAN, Gigabit&10 G Ethernet, SDH/SONET, Fiber Channel, Roadway safety, Data-video Transmission, Long-distance monitoring, Military and many other fields.

The aim of HTFuture is provide you quality products, gratified service and fast delivery